Fun To Do PDMS vat repairing kit

Fun To Do for vat repairing in DLP/LCD/SLA 3D pritnters.

Repairing your resin tank is now easy and cheap!

With the PDMS Kit you can repair the silicone lining of your 'Vat' or 'Tank' as they call it at Formlabs.This means that you don't have buy a brandnew Tank everytime your lining gets blurred by 'ghosting'.Just remove carefully the old lining, clean the tank and pour in a new layer, let it dry and, hey presto, your tank is like new again!The PDMS kit contains 250gr of material, enough for 2 - 4 replacements of your Vat/Tank linings (depending on the layer thickness and the printertype)Suitable for all machines with a PDMS (Silicone) Vat/Tank lining. (B9,Form1, Form1+,Form2 and the likes)

How to handle the PDMS kit, and how to replace the PDMS layer in your Formlab’s tank.

Mixture: To use the PDMS you have to mix it at a 1 to 12 ratio. (1 part of Activator = 12 parts of PDMS) For the Form1 you can use anywhere between 46 to 92gr. of PDMS

(Some people use 92gr for two tanks, but personally I find that a bit too thin of a layer)

Replacing your damaged PDMS layer: Before removing the old PDMS layer wipe clean the vat + edges with a cloth using a small amount of IPA to remove the worst of the resin. (You don’t want the resin spill on the window of the tank.)

To remove old PDMS use a knife to break the seal in a corner. Be careful not to damage or scratch the Vat itself. Then use a fork or similar, dig it into the PDMS a little, facing the corner then peel away from corner to remove. Peel away the rest by hand and remove all remaining bits also around the joints where the clear section is glued to the orange section. After all the old PDMS has been removed, clean the VAT with a mild detergent in hand warm water (similar to doing the dishes). Use a very soft cloth to clean, to prevent scratches on the bottom of the tank. When drying, try to remove all smudges, dirty fingers etc. from the tank bottom. Use a soft cloth, like a handkerchief (a clean one)

As for the volume I use 85ml of silicon for the Form1, Depending on the tank you cured you may need to change the first layer height in the software.(under printers) I normally make a little mark at the height of the original height and fill the VAT with the new PDMS to exactly to the same height. When mixing the two components of the PDMS, air bubbles will appear in the mixture, don’t worry, they will disappear by themselves if you pour the mixture in a warm environment (+-20C) You have enough time to do the job, you can work the mixture for about 15-20 minutes. After pouring, level the mixture by tilting the tank in two directions, it is really important that the PDMS dries while the tank is level! Leave in a clean warm area to cure for 48 hours check that the tank is on a level surface, also cover to reduce any dirt reaching the tank.

I pour the remaining PDMS in a plastic cup, this way you can check after about 24 hrs how curing is going, when the curing is too short the PDMS rips quite easily when pulled.